In the railroad industry, prior to the introduction of the more powerful and efficient diesel engine in locomotives, such railroad locomotives were generally underpowered. Consequently, in order for these underpowered locomotives to start a train consist, having several cars, in motion, it was necessary to provide each end of a railway car with a draft gear assembly. These draft gear assemblies provided a requisite amount of slack required in the coupling arrangement between adjacent ends of the several cars making up the train consist. As is generally well known, in the railway art, this slack enabled start-up movement of the lead car and each of the following cars in succession. In other words, during start-up the locomotive would begin taking up the slack between it and the lead car first, then the slack in each following car in turn would be taken up. This start-up procedure enabled the lower powered locomotive to gain sufficient momentum to start the train consist in motion.
In addition, it is equally well known, in the railway art, that the buff and draft forces generated and applied to the railroad cars in such a coupling arrangement, during in track operation of the train consist were normally absorbed by these draft gear assemblies. Such draft gear assemblies were mounted in a draft gear pocket located in a yoke positioned within the center sill member of the railway car. The railway car coupler mechanism is connected to the yoke by means of a striker plate casting. Nevertheless, these prior art coupling arrangements resulted in undesirable dynamic loading on both the car bodies and their contents. These dynamic loadings usually result in considerable wear of the various coupling components on the car and depending upon the contents of such car they can even result in damage to such contents. It is obvious that wear of the coupling required considerable maintenance.
Since the introduction of the more powerful diesel locomotive in the modern railroad industry, it has been discovered the slack is no longer necessary to start the train consist in motion. In other words, a diesel locomotive provides the capability of starting the movement of a train consist, containing multiple cars, without the need for considerable amounts of slack being provided by the draft gear assemblies in the car coupling arrangements. As a result, slackless drawbar assemblies have come into widespread use in the railroad industry as the connecting means for joining together adjacent ends of a pair of railway cars. It has been demonstrated that these slackless drawbar assemblies enables the buff and draft forces generated by in-track movement to be distributed throughout the car center sill member to all of the railway cars in the train consist with less damage to both the car components and cargo.